1. Field of the Invention
This invention is related to an optical switching apparatus used in an optical network for voice and data communications. More particularly, embodiments of the present invention provide for an optical switching device and method for fabricating, forming or producing an optical cross-connect switching device.
2. Description of the Related Art
Strong growth of optical networks for voice and data communication results in huge demand for high data rate information transfer capabilities. To enable such transfer capabilities, dense wavelength division multiplexing (DWDM) technology has been developed which allows transfer of multiple wavelength over the same fiber leading to data transfer rates up to 40-100 Gb/s. High speed switching and routing devices comprise the core elements of the optical networks and allow dynamic control of the data traveling over the optical network. Furthermore, high data transmission rates impose strong requirements on the functionality of the switching devices.
Optical cross-connect space division switches based on optic-electro (OE) deflection of the light beam have great potential for future implementation in high speed optical networks. One of the basic concerns is the switching time and a capability of handling a great number of input and output channels, e.g., up to 4000×4000 by the year 2003, as well as reliability and cost factors. Existing optical switching devices which employ signal conversion from optical into electrical and back into optical do not satisfy those requirements. Having very low switching times switching matrixes can be designed to connect very large number of input and output (I/O) ports. Such switches may be built from an assembly of simple digital optical switches where each can redirect one input signal into two possible output ports. However, optical cross-connect switching elements are more useful for large-scale implementations. These devices require large-scale monolithic switch arrays to perform switching functions. Although, the main principle of the optical cross connect switching based on the light beam deflection is well known, a robust, reliable, low cost and extendable integration process for such type of switching device is not available.
Currently, the main optical switching products on the market (e.g. Lucent's Lambda-router) are based on MEONIS technology, which employs rotating micro-mirrors to deflect light. However, these optical switching devices are not very reliable due to many moving parts, and also the switching time is limited by the mechanics of the mirrors. It is desirable to improve the reliability of the many moving parts of the optical switching devices and to overcome the limitation of the switching time in these devices due to the mechanics of the micro-mirrors.
There are several other optical switching technologies which are still not well represented in the market due to various technological and economic difficulties. Such optical switching technologies include by way of example only: the bubble switch from Agilent Technologies Inc., switches based on liquid crystals, and thermo-optic and electro-optic (EO) effects, etc. Most of these devices are still in the R&D stage. Some of those technologies including EO switches may be applicable for high speed, low cost, high reliability, and high I/O port count products. However, as of today no proven technology has been developed which can satisfy the above-mentioned requirements.
Therefore, what is needed and what has been invented is an improved optical switching device and method for fabricating the improved optical switching device. What is further needed and what has been invented is an integration process which allows for fabrication of a non-blocking optical cross-connecting switching matrix possessing a large number of input and output channels.